Current research in structural biology is focused on understanding the role of enzymes and proteins in regulating cellular metabolism and the way drugs bind to proteins. Macromolecular crystallography provides 3D distributions of atoms which is extremely important for bioengineering and may provide tools essential for understanding the progression and ultimately controlling such diseases as cancer and AIDS. Intense X-ray sources like the synchrotron beam sources as well as the new beam lines now under development, such as the Advanced Photon Source, hold great promise for macromolecular crystallography. However, they have not yet realized their potential due to the lack of an appropriate position sensitive sensor. To address these specific needs, we are currently carrying out the research to develop an improved, large area, X-ray imaging sensor coupled to a CCD using a fiberoptic taper demagnifier. Our early work has produced a modified sensor with a combination of greater light output, resolution, and fast decay time than standard phosphors, allowing the imaging devices to be used with synchrotron fluxes. In Phase II we plan to complete the research and development of the sensor and will also design a detector with larger field of view optics to realize a novel imaging system. Its benefits to macromolecular crystallography will be assessed using laboratory and synchrotron X-ray sources. PROPOSED COMMERCIAL APPLICATION: Besides the determination of biological structures, the proposed detector would find widespread use in instrumentation where high resolution X-ray detectors are used. X-ray imaging instruments currently have a very large commercial market. They may be applied to medical imaging, X-ray astronomy, nondestructive testing, and basic physics research.